Provide an API to the example window manager app that supports closing a window.

mojo/services/public/cpp/view_manager/lib/view.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/services/public/cpp/view_manager/view.h"
 
 #include "mojo/services/public/cpp/view_manager/lib/view_manager_private.h"
 #include "mojo/services/public/cpp/view_manager/lib/view_private.h"
 #include "mojo/services/public/cpp/view_manager/view_observer.h"
 #include "ui/gfx/canvas.h"
@@ skipping 61 matching lines @@
     : id_(ViewManagerPrivate(manager).synchronizer()->CreateView()),
       node_(NULL),
       manager_(manager) {}
 
 View::View()
     : id_(-1),
       node_(NULL),
       manager_(NULL) {}
 
 View::~View() {
-  ScopedDestructionNotifier notifier(this);
-  if (manager_)
-    ViewManagerPrivate(manager_).RemoveView(id_);
+  {
+    // TODO(beng): I'm not sure I like these scoped destruction notifiers.
+    //             When they fall out of scope |this| is toast.
+    ScopedDestructionNotifier notifier(this);
+    if (manager_)
+      ViewManagerPrivate(manager_).RemoveView(id_);
+  }
 }
 
 void View::LocalDestroy() {
   delete this;
 }
 
 }  // namespace view_manager
 }  // namespace mojo